Heading off the obesity epidemic: DNA tests at five can tell if a child will be fat at 14

Samples taken when a child is five can indicate how much body fat they will have at 14 (Picture: File/PA)

A DNA blood test can predict obesity levels in children as they grow up, scientists claim.

Samples taken when a child is five can indicate how much body fat they will have at 14, researchers say.

The test checks a gene called PGC1 which regulates fat storage.

Scientists hope the discovery could help find ways to stop children becoming obese.

They used DNA from 40 children who took part in a project studying 300 youngsters in Plymouth from the age of five to 14. The children were assessed annually for factors related to type 2 diabetes, such as the amount of exercise they did and the amount of fat in their body.

A team in Southampton extracted DNA from their blood samples to test for epigenetic switches.

These switches take place through a chemical change called DNA methylation, which controls how genes work.

The team found that a rise in DNA methylation levels of ten per cent at five years old was associated with up to 12 per cent more body fat at 14. Results were independent of the child’s gender, the amount of physical activity and the timing of their puberty.

The study, which also involved experts from the University of Exeter and the University of Plymouth, is published in the journal Diabetes.

Dr Graham Burdge, of the University of Southampton, said: ‘The results of our study provide further evidence that being overweight or obese in childhood is not just due to lifestyle, but may also involve important basic processes that control our genes.

‘We hope that this knowledge will help us to develop and test new ways to prevent children developing obesity which can be introduced before a child starts to gain excess weight.

‘However, our findings now need to be tested in larger groups of children.’